Some releases can experience problems restoring temporary dbspaces. This normally manifests itself as a downed chunk after the restore. This chunk can not be dropped because the engine still believes there is valid data contained within the chunk. Informix Technical Support are required to clear this problem.

If the engine can not be upgraded to avoid the problem, then drop the temporary dbspaces before the archive and put them back later.

Informix will only restore if the tapes are presented in the correct order. However if the order is unknown then the tape sequence can read from the header of the tape, it should be at byte 15 and 16 on the tape.

There are a number of reasons why the database won't fit on the tape. Probably the two most common are

The tape isn't really as long as it advertised.

There is compression in the way and you are not acheiving the compression rate that the manufacturer claims is possible. For example a 70GB DLT tape is in fact a 35GB tape with a 2:1 compression ratio. There are no hard and fast rules for estimating the amount of compression that will be seen.